Zalanthe
Citizen of Zooville
I feel like this question only makes sense on a premise which isn't absolute. There's no basis for the traits that has you considered a zoophile to be abnormal, only the situation and application of them that goes against a set cultural norm. So based on that, I'd say that they are made in all cases. In fact, I'd say this goes for far more than just this, but pretty much all sexuality is rooted in nurture, while nature only weighs the dice towards certain outcomes.